The present invention relates to ventilating structures for use in electronic apparatus such as video projectors. The present invention also relates to ventilating structures for use in video projectors having a projecting lens in their front end section. The present invention also relates to structures for mounting a ventilating fan unit for use in electronic apparatus such as video projectors.
In homes and offices, video projectors are being popularly used for projecting video images on a screen. Generally, each of the video projectors includes a built-in light source of great light quantity for projecting video images on a large screen. For example, the light source is in the form of an incandescent lamp that consumes electric power in the order of 150 watts. Electronic circuitry for processing video signals in the video projector also consumes electric power more than 50 watts and thus the video projector as a whole consumes power exceeding 200 watts, so that a considerable amount of heat is generated in the interior of the video projector. Because sufficient heat dissipation is not attainable by natural ventilation, an electric fan is normally used to compulsorily introduce external air into the interior of the video projector or discharge heated air from the interior, so as to cool the electronics and lamp in the interior of the video projector.
However, because the video projector is used quite near the user or video viewer(s), the video viewer(s) would be significantly disturbed by great noise produced by the ventilation operations. Further, heated air discharged from the interior of the video projector would greatly displease and disturb the video viewer(s). Therefore, it has been conventional to support the fan unit at a plurality of corners thereof by means of supporting members each made of a rubber or other resilient material, in order to absorb vibrations of the fan unit utilizing the resiliency of the supporting members. However, because characteristics of the rubber supporting members tend to be greatly varied by temperature changes, the resiliency of the supporting members would be weakened by the heated exhaust air so that the vibrations of the fan unit are undesirably transmitted to the outer case of the video projector. Further, with the fan unit thus supported at its corners, horizontal vibrations of the fan unit can not be sufficiently absorbed.